Impact of Dapivirine and Placebo Vaginal Rings on the Microbiota of Adolescent, Lactating, and Postmenopausal Females.

BACKGROUND: A 25-mg dapivirine vaginal ring has been demonstrated to reduce risk of human immunodeficiency virus (HIV) acquisition in nonpregnant adult women. In this secondary analysis of studies conducted in US adolescent, lactating, and postmenopausal females, vaginal microbiota was assessed prior to and after ring use, and between dapivirine and placebo ring users. METHODS: Vaginal fluid swabs were collected before and after product use for the evaluation of microbiota using Nugent criteria, quantitative culture, and quantitative polymerase chain reaction. RESULTS: Vaginal ring use did not impact bacterial vaginosis prevalence among the 3 populations and was associated with minimal shifts in microbiota. Adolescents in both arms demonstrated an increased prevalence of Lactobacillus crispatus and a decrease in quantity of Megasphaera lornae. Postmenopausal active and placebo ring users demonstrated an increased prevalence of lactobacilli and non-albicans yeast, while dapivirine ring users demonstrated an increased prevalence of Candida albicans and increased quantity of group B Streptococcus and non-albicans yeasts. Prevotella species were increased in lactating women, whereas Prevotella timonensis increased in prevalence and concentration among adolescent and postmenopausal females and Prevotella bivia increased in prevalence among adolescent dapivirine ring users. CONCLUSIONS: Dapivirine vaginal ring use was associated with minimal changes in the vaginal microbiota that are likely not clinically significant.

Bacterial species colonizing the vagina of healthy women are not associated with race.

The vaginal microbiota of 36 white versus 25 black asymptomatic women were compared using both cultivation-dependent and -independent identification. Significant differences by race were found in colonization and density of bacterial species. However, exclusion of 12 women with bacterial vaginosis by Nugent criteria resulted in no significant differences by race.

Survival of vaginal microorganisms in three commercially available transport systems.

Transport systems are used to collect and maintain the viability of microorganisms. Two Amies media based transport systems, BD CultureSwab™ MaxV(+) Amies Medium without Charcoal (MaxV(+)) and Fisherfinest® with Amies gel Transport Medium without charcoal (Fisherfinest®) were compared to a Cary-Blair media based transport system, Starswab® Anaerobic Transport System (Starswab®), for their capacity to maintain the viability of 17 clinical microorganisms commonly isolated from the vagina (Lactobacillus crispatus, L. jensenii, L. iners, group B streptococci, Candida albicans, Escherichia coli, Enterococcus faecalis, Atopobium vaginae, Peptoniphilus harei, Mycoplasma hominis, Gardnerella vaginalis, Dialister microaerophilus, Mobiluncus curtisii, Prevotella amnii, P. timonensis, P. bivia, and Porphyromonas uenonis). Single swabs containing mixtures of up to five different species were inoculated in triplicate and held at 4 °C and room temperature for 24, 48, 72, and 96 h (h). At each time point, swabs were eluted into a sterile salt solution, serially diluted, inoculated onto selected media, and incubated. Each colony type was quantified and identified. A change in sample stability was reported as a ≥1 log increase or decrease in microorganism density from baseline. Overall, the viability of fastidious anaerobes was maintained better at 4 °C than room temperature. At 4 °C all three transport systems maintained the viability and prevented replication of C. albicans, E. faecalis, GBS, and E. coli. Microorganisms having a ≥1 log decrease in less than 24 h at 4 °C included A. vaginae, G. vaginalis, and P. uenonis in Starswab®, L. iners, A. vaginae, and P. amnii in MaxV(+), and A. vaginae, G. vaginalis, P. bivia, and P. amnii in Fisherfinest®. At 48 h at 4 °C, a ≥1 log decrease in concentration density was observed for P. harei and P. amnii in Starswab®, G. vaginalis, P. bivia and P. uenonis in MaxV(+), and L. iners, P. harei, P. timonensis, and P. uenonis in Fisherfinest®. Overall, at 4 °C the viability and stability of vaginal microorganisms was maintained better in the Cary-Blair based transport system (Starswab®) than in the two Amies based transport systems.

Optimization of processing female genital tissue samples for lymphocyte analysis by flow cytometry.

PROBLEM: A variety of methods have been used to process cervical cytobrush and genital tissue for flow cytometric evaluation of immune cell populations. We sought to optimize genital tract specimen processing and to determine if blood could be used as a model for assessment of tissue processing methods. METHOD OF STUDY: Cervical cytobrushes, PBMCs, and genital tissue samples (cervical and endometrial biopsies) were subjected to varying processing conditions to characterize the effects on cell yields, lymphocyte viability, and surface receptors. We exposed PBMC and tissue specimens to varied collagenase types, concentrations, and exposure durations and cytobrushes to immediate vs delayed processing with/without vortexing. RESULTS: PBMCs and tissues exposed to varying enzymatic digestion conditions demonstrated stability of some cell surface receptors, including CD3+ , CD4+ , and CD8+ , while others, including CCR6+ , were cleaved when exposed to any concentration of collagenase B, or ≥0.25 mg/mL of collagenase D. We observed increased CD69 expression (marker of cell activation) after exposure to collagenase B. Neither a 2-hour delay in cytobrush processing nor vortexing at a setting of 50% for 30 seconds had significant impacts on viability or quantities of genital immune cells of interest. CONCLUSION: Although tissue digestion with collagenase D was sufficient to recover and analyze cells from endometrial biopsy specimens, cervical biopsy specimens required a limited exposure to collagenase B at 1 mg/mL to optimize cell yield and viability for cytometric analysis. PBMCs can be used as a model to assess the impact of tissue processing on co-receptor expression and to optimize methods prior to study implementation.